Field of the Invention
The present invention relates to an endoscope and a hardness adjustment device, and particularly relates to an endoscope and a hardness adjustment devise capable of adjusting the hardness of a flexible portion of the endoscope.
Description of the Related Art
Typically, medical diagnosis utilizing an endoscope has been broadly performed in a medical field. In particular, an image in a body cavity is acquired by an endoscope configured such that an image pickup element such as a charge coupled device (CCD) is embedded in a tip end portion of an endoscope insertion portion to be inserted into the body cavity. Signal processing is performed for such an image by a processor device, and then, the image is displayed on a monitor. A doctor observes the displayed image for the purpose of diagnosis, or inserts a treatment tool through a treatment tool insertion channel to perform the procedure for collecting a sample or cutting a polyp, for example.
Generally, an endoscope is substantially configured such that an operation portion to be grasped and operated by a practitioner and an insertion portion to be inserted into a body cavity etc. are continuously provided and that a universal cable for connection to a connector portion etc. is drawn from the operation portion. The universal cable protrudes from the operation portion, and the other end portion of the universal cable is detachably connected to an optical source device or a processor device.
The insertion portion of the endoscope includes a flexible portion having flexibility so that the insertion portion can be also inserted into a complicated curved insertion path. However, a tip-end-side direction of the insertion portion is not fixed due to the flexibility, leading to a problem that it is difficult to insert the insertion portion in a target direction. Moreover, in order to perform certain procedure or observation, the insertion portion might sometimes need to be fixed in a shape when the insertion portion has been inserted into the body cavity.
For these reasons, an endoscope configured such that a coil spring (a helical spring) and a hardness adjustment unit including a wire inserted into the coil spring are arranged in a flexible portion (a flexible tube portion) has been disclosed in Japanese Patent Application Laid-Open No. 49-65086. According to the endoscope of Japanese Patent Application Laid-Open No. 49-65086, a practitioner operates an operation ring provided at an operation portion to compress the coil spring in the axial direction thereof, thereby increasing the degree of flexibility (the hardness) of the flexible tube portion.
In the endoscope of Japanese Patent Application Laid-Open No. 49-65086, a wire fixing portion to which a base end portion of the wire is fixed is provided in the operation portion. Moreover, a rotary ring provided with a helicoid groove is provided in the operation portion, a mover being fixed to a base end portion of the coil spring and being inserted into the helicoid groove. This rotary ring is rotatably operated by the operation ring. That is, a fitting portion in which the mover is fitted into the helicoid groove and the above-described wire fixing portion are provided in the operation portion. Moreover, in the endoscope of Japanese Patent Application Laid-Open No. 49-65086, the wire fixing portion and the fitting portion are arranged on an extension of the coil spring along the axial direction of the coil spring.